Concerns around public health recommendations on face mask use among individuals who are not medically diagnosed with COVID-19 supported by a systematic review search for evidence. CURRENT STATUS: POSTED

have been provided to individuals who are not yet medically diagnosed with COVID-19, which is significantly a large population. Face masks are being used by individuals who are not medically diagnosed with COVID-19 as a means to limit the spread of COVID-19 in several countries around the world. While some countries recommend the use of face masks, other countries strictly do not recommend their use to limit the transmission of COVID-19 among individuals who are not medically diagnosed with COVID-19. This paper critically analyses public health recommendations provided to this population regarding face mask use by public health and health professionals of different countries supported by a systematic review that searched for evidence on face mask use among this specific population in limiting the spread of COVID-19. groups

This paper shows that current public health recommendations meet none of these requirements which is concerning and should be avoided in future outbreaks.
Medical or surgical masks 2 or N95 respirators, 3 hereinafter referred to as face masks, are being used by individuals who are not medically diagnosed with COVID-19 as a means to limit the spread of the virus in several countries across the globe. The use of face masks as a means to limit the spread of COVID-19 has been discouraged or not recommended for populations who are not medically diagnosed with COVID-19 in various countries. While countries such as Australia, Canada and the United States of America do not recommend that this specific population wear face masks to limit the potential spread of COVID-19, health officials in countries like China, Indonesia, and the Philippines have supported the use of face masks to limit the spread of COVID-19 among this specific population.
[1] [2] [3] [4] [5] [6] [7] [8] Recommendations that have been provided by health professionals regarding wearing a face mask to limit the spread of COVID-19 among individuals who are not medically diagnosed with COVID-19 include a mix of varying information as provided below. "As long as we use it correctly, a [surgical] mask is enough protection from the virus or bacte masks should be used mainly by sick people to prevent the spread of the virus while coughin also protects healthy people from being infected while in public places." [8] China "At least two Chinese provinces now require face masks to be worn in public." [7] British Columbia Centers for Disease Control and Prevention's (BCCDC), Canada "It may be less effective to wear a mask in the community when a person is not sick themse may give a person a false sense of security and are likely to increase the number of times a p touch their own face -to adjust the mask, etc." [3] The chief medical officer of Ontario, Canada "'We never recommend wearing a mask in public' because many people don't use them prop Reaching underneath them to touch your face, for instance, spreads germs. N95 respirator m named because they're designed to stop 95 percent of small particles from reaching the nose only work if they fit properly, which they won't for children or people with facial hair." [1] University of Toronto, Immunology professor, Canada "The issue with [the surgical mask] is it obviously doesn't protect your eyes and they're loose there's an opportunity for something to come within areas where it's not tightly fitted, throug or neck. The coronavirus is transmitted through human-to-human contact, which includes dro produced while sneezing or coughing. Wearing a surgical mask, that is very well-fitted, would amount of virus you'd be exposed to." [9] The Center for the National Center for Immunization and Respiratory Diseases, USA "'We don't routinely recommend the use of face masks by the public to prevent respiratory il certainly are not recommending that at this time for this new virus. We want our actions to b based and appropriate to the current circumstance' which did not justify the use of face mask who have not been directly exposed to the virus". It is important to make a note of the population these recommendations have been provided to. This population is generally called "healthy individuals". However, they will be referred to as "individuals who are not medically diagnosed with COVID-19" in this paper because a person can be "healthy" from outside but can be carrying the virus. This population, "individuals who are not medically diagnosed with COVID-19", include those who may have been exposed to the virus and are asymptomatic; pre-symptomatic; symptomatic but have not yet been diagnosed with COVID-19 and therefore not aware that they have COVID-19 and; those who have not been exposed to the virus.
The first three groups of individuals are impossible to distinguish from one another in terms of whether they carry COVID-19 and a risk of spreading the virus in public spaces. This paper discusses the concerns around the contradicting public health recommendations that have been provided to this specific population regarding face mask use followed by a systematic review that looks for evidence in order to evaluate current public health recommendations in the context of available evidence.

Methods
To carry out the systematic review portion of this paper, databases Cochrane Library and 3) studies that were in English.

Exclusion criteria
If the abstract did not relate to the effectiveness of face masks in limiting the spread of COVID-19 in community settings, the study was excluded. Commentaries were excluded.

Results
This systematic review search did not find any studies that investigated the effectiveness of face masks in limiting the spread of COVID-19 among those who are not medically diagnosed with COVID-19 to support current public health recommendations ( Figure 2). The lack of evidence on the use of face masks in limiting the spread of COVID-19 among this population and how this finding has an effect on the current public health recommendations is discussed below.
Insert Figure 2: Schematic diagram of the literature search.

Discussion
The systematic review portion of this paper did not find any research studies that investigated the effectiveness of face mask use in tackling this specific virus in this specific population. This finding questions the basis of contradicting and varying public health recommendations that have been provided by public health and health professionals on face mask use around the world since the beginning of COVID-19 outbreak. The concerns around current public health recommendations in the context of this finding is discussed below.

Evidence-based public health recommendations
One of the important requirements for further research on this subject is the need for evidence-based public health recommendations. Practicing evidence-based approaches in public health increases the availability of higher quality information, likelihood of successful prevention programs and policies, and efficiency in the use of resources. [ programs, developing policies and evaluating progress, which also applies to when providing public recommendations. [14] [15] Therefore, it is best that recommendations are based on best available scientific evidence whether the recommendation is to wear or not to wear face masks in community settings among different types of sample populations. Recommendations that are not supported by scientific evidence can create controversy and confuse the public as well as health authorities around the world, creating contradicting and inconsistent recommendations. Such recommendations not only create confusion and controversy but also increase the risk of unnecessary spread of the infection.
As an example, in a situation where an asymptomatic, pre-symptomatic or symptomatic individual with COVID-19 who has not yet been medically diagnosed, who is not wearing a face mask, coughs or sneezes without covering their face, they could be releasing respiratory droplets. WHO states that "people can also catch COVID-19 if they breathe in droplets from a person with COVID-19 who coughs out or exhales droplets. This is why it is important to stay more than 1 meter (3 feet) away from a person who is sick." [16] If these individuals are not wearing a face mask, the risk of spreading the infection through coughing or sneezing out droplets is higher. On the other hand, if healthy individuals in close proximity are not wearing face masks, they may be at a higher risk of contracting COVID-19 through respiratory droplets. [16] This kind of transmission is not rare especially in public transit during rush hour in any part of the world.
By providing recommendations against the use of face mask in the above situation, health authorities may be implying that wearing a face mask is not effective in protecting a healthy individual in this situation. diabetes, heart disease and renal or chronic lung disease appear to be more vulnerable to becoming severely ill with COVID-19 directly or through a family member. [19] [20] It may be best to err on the side of caution when making recommendations to the public regarding face mask use in the absence of evidence to reduce the risk of potential transmission to the most vulnerable populations.

Evidence and knowledge transparency of public health recommendations with the public
Transparency during a health emergency is extremely important because information plays an important role in maintaining core public health objectives. [21] During a situation where the public is at risk of a real or potential health threat, there might be delays in obtaining treatment options, interventions may be lengthy and there may be limited resources available. [21] Public recommendations and guidelines, therefore, is the most important tool available in managing a risk during an outbreak. [21] According to public health professionals, providing proactive guidelines and having transparency is an organizational responsibility and it is also the most successful method to grasp a control of public discourse, media reports and customer relations related to the situation. [21] Scholars in the field of Public Health Ethics and Pandemic Influenza Planning have also emphasized the importance of transparency in managing infectious disease outbreaks. [ "transparency is also a necessary, if not sufficient, condition for accountable decision-making and for the promotion of public trust." [21] Transparency about the unknown and the known are both equally important to build and promote public trust. [21] Therefore, in the case of the COVID-19 outbreak, whether recommendations are provided in the absence of evidence or whether they are evidence-based must be transparent to the public. Where there is evidence transparency, the public is more likely to understand what scientific evidence recommendations are based on and therefore, be more confident in adhering to recommendations.
For example, in the case of medical professionals' request to halt the hoarding of face masks among the public, merely saying "masks do not help" has not been helpful in preventing the public from continuing to buy face masks, perhaps unnecessarily. [25] [26] With scientific evidence of their ineffectiveness in limiting the spread of COVID-19 among those who are not medically diagnosed with COVID-19, public health and health professionals can be consistent and confident when recommending the public not to buy face masks and as a result avoid situations such as running out of face masks for healthcare workers.
Some of the recommendations provided to the public suggest that the incorrect use of face masks may have potential risks as discussed earlier. These potential risks can be minimized by educating the public about the risks and how to correctly use face masks to prevent the risks. A common concern brought up in current recommendations is about the false sense of security that face masks may bring to those who use them. [17] [2] [3] A false sense of security is the feeling of being safer than one really is. [27] In the context of COVID-19 and face mask use, a false sense of security means that the individuals may feel that they are safe from contracting COVID-19 because they are wearing face masks while that may not be the case. In the case of such concern, the public must be educated about the "false sense of security" that wearing a face mask may bring to individuals and how it may contribute to the increased risks associated with wearing face masks or neglecting other precautionary actions. Some recommendations emphasize that other precautionary methods are more important than wearing a face mask while some suggest face masks are only effective in combination with other precautionary practices. [2] [9] All of the above information must be shared effectively with the public through reliable media when making public health recommendations. It is imperative to be transparent with the public about the current evidence and knowledge public health recommendations are based on in order to successfully achieve the goals behind the recommendations.

Global alignment on public health recommendations
Public health recommendations must align globally. Varying recommendations can have a negative effect on countries around the world, especially in developing countries. In some developing countries, there is a severe lack of dissemination of credible information to the public as well as a concerning lack of knowledge among the general population to be able to identify and distinguish credible information from noncredible information. In these populations, most people tend to trust what is typically seen on social media or other online platforms. For example, a consult physician in Sri Lanka says that, "containing the panic and dissemination of misinformation has proved tougher than fighting the actual disease ." [28] [29] In the case of face mask use, when people in developing countries observe on online platforms, a wide use of face masks to limit the spread of COVID-19 or recommendations advising the use of face masks, they may be likely to follow these recommendations without questioning the evidence behind  Although COVID-19 has not been declared as a pandemic yet (as of 25 Feb 2020), in case of a pandemic, knowing the effectiveness of masks ahead of time of the crisis would be extremely useful.
While research surrounding the biology, epidemiology and behaviour of the new virus is extremely important and a priority at the moment, studying every method of prevention is equally important as prevention will not only provide the public with knowledge and instructions that they can rely on and confidently practice, but also save lives and reduce suffering and the expenditure of healthcare resources. This research is important, especially today because there is an immense use of face masks among the public around the world despite the uncertainty around the effectiveness of face masks. Such popular practices must be given immediate attention and studied thoroughly.

Limitations
The author had to use information outside of academic literature such as information from media outlets and newspapers (all cited) due to the lack of specific information in academic literature, such as public health recommendations provided to those who are not medically diagnosed with COVID-19 regarding face mask use. While this may be a limitation, sometimes it is imperative to use available information to bring attention to public health concerns. The systematic review search being limited to the English language is a limitation of this review. It is a possibility that there are research studies published in other languages that have not been translated to English and therefore, are not included in this review. This review being conducted by one reviewer might be a limitation as well, as having more than one reviewer may be advantageous.

Conclusions
The finding of the systematic review search, which is a lack of scientific evidence, questions the basis of inconsistent and contradicting public health recommendations that have been provided to the public at a very early yet a crucial stage of an outbreak. This paper calls for 1) evidence-based public

Declarations
Ethics approval and consent to participate: Not applicable.
Consent for publication: Not applicable.
Availability of data and materials: The datasets used and/or analysed during the current study are available from the corresponding author on reasonable request.
Competing interests: The author declares that they have no competing interests.
Funding: No funding received.

Authors' contributions
Keshini Madara Marasinghe led and conducted the review and discussed the findings.

Acknowledgements
The author would like to thank the following individuals for their professional advice and feedback, technical input, and review of this literature review.
Dr. Jostacio Moreno Lapitan, WHO Loïc Garçon, WHO Bridget Lee, MPH Footnotes 1 Individuals who are "not medically diagnosed with COVID-19" include those who may have been exposed to the virus and are asymptomatic; pre-symptomatic; symptomatic but have not yet been diagnosed with COVID-19 by a healthcare professional therefore may not be aware that they have COVID-19 and; those who have not been exposed to the virus. 2 United States, Centers for Disease Control and Prevention (CDC) describes a surgical mask as a face mask that provides barrier protection against large particle droplets that can be released when a wearer talks, coughs, or sneezes. [33]CDC notes that medical or surgical masks do not effectively filter inhaled small particles, fumes, or vapors. [33] They are "primarily used to protect patients and healthcare workers from people who may have a respiratory infection" according to CDC. [33] 3 The Food and Drug Administration (FDA) of the United States, describes N95 respirators as masks that are designed to "achieve a very close facial fit and very efficient filtration of airborne particles." [34] N95 respirators block at least 95 percent of very small (0.3 micron) test particles minimizing the wearers' respiratory exposure to airborne infectious agents. [34] [35] FDA also states that if N95 masks are properly fitted, the filtration capabilities of N95 respirators surpass those of surgical masks. [34] However, even a properly fitted N95 respirator does not completely eliminate the risk of illness or death according to FDA. [34] Figures Figure 1 Database search terms.

Figure 2
Schematic diagram of the literature search.

Supplementary Files
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